1. Field of the Invention
This invention relates to casings of mechanical mountings for interchangeable lenses for use with motion picture and still cameras, and a camera system using the same.
2. Description of the Prior Art
With recent advances in electronification of camera mechanisms the field of still cameras adapted for use with interchangeable lenses has already developed a system in which a diaphragm device is incorporated as a unit in a mechanical mounting for the interchangeable lenses, and the diaphragm information representative of the aperture size of the controlled diaphragm device is electrically transmitted through a suitable electrical intermediary to the camera housing wherein it is presented to the camera operator. Also in the field of motion picture cameras adapted for use with interchangeable lenses, there has been divised a system in which a motor either for driving an EE diaphragm device, or for driving a zoom-operating means is associated as a unit with a mounting mechanism for interchangeable lenses, and the terminals of the motor are connected through an electrical intermediary to an exposure control circuit and a power source provided in the camera housing. In this manner, the motor is operated in response to signals or electric power supply from the camera housing.
Such conventional systems, however, are realized in mechanical mountings for interchangeable lenses in such ways as not to permit selection of drive mechanisms for demountably mounting in the mechanical mounting. For example, a mechanical mounting which is designed for association with an EE diaphragm drive mechanism connot be operated with other than the EE diaphragm drive mechanism incorporated therein in unison, while a mechanical mounting which is designed for association with a zoom drive mechanism connot be operated with other than the zoom drive mechanism incorporated therein in unison. Therefore, the cost of production of a lens unit employing such a combination of mounting and driving mechanism for an interchangeable lens system is considerably raised. Further, in several photography applications requiring production of different photographic effects by the use of different interchangeable lenses, there must be provided a series of lens units incorporating respective mechanisms adapted for use in different photography applications. This creates problems such that the cost necessary for acquiring the series of lens units by large, and the handling of the lens units when carrying with and when interchanging them is very troublesome.